From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: Re: [PATCH v5 5/6] iommu/mediatek: Add mt8173 IOMMU driver Date: Wed, 14 Oct 2015 14:53:09 +0200 Message-ID: <20151014125309.GO27420@8bytes.org> References: <1444357388-30257-1-git-send-email-yong.wu@mediatek.com> <1444357388-30257-6-git-send-email-yong.wu@mediatek.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1444357388-30257-6-git-send-email-yong.wu-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Yong Wu Cc: Mark Rutland , Catalin Marinas , Will Deacon , youhua.li-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org, Thierry Reding , k.zhang-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kendrick.hsu-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org, arnd-r2nGTMty4D4@public.gmane.org, Tomasz Figa , Rob Herring , linux-mediatek-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Matthias Brugger , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, pebolle-IWqWACnzNjzz+pZb47iToQ@public.gmane.org, srv_heupstream-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org, Sricharan R , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, Daniel Kurtz , Sasha Hauer , Lucas Stach List-Id: devicetree@vger.kernel.org On Fri, Oct 09, 2015 at 10:23:07AM +0800, Yong Wu wrote: > + /* > + * There is a domain for each a iommu device in normal case. > + * But MTK only has one iommu domain called the m4u domain which all > + * the multimedia HW share. Here we reserve one as the m4u domain and > + * free the others. > + * > + * And the attach_device that from __iommu_setup_dma_ops > + * will be called earlier than probe. > + */ Okay, with this being the case, you need to put all devices behind one IOMMU into the same iommu-group, because the IOMMU can't really isolate the devices from each other. > +static int mtk_iommu_add_device(struct device *dev) > +{ > + struct iommu_group *group; > + struct mtk_iommu_client_priv *priv; > + struct mtk_iommu_domain *m4udom; > + struct iommu_domain *domain; > + int ret; > + > + if (!dev->archdata.iommu) /* Not a iommu client device */ > + return -ENODEV; > + > + group = iommu_group_get(dev); > + if (!group) { > + group = iommu_group_alloc(); > + if (IS_ERR(group)) { > + dev_err(dev, "Failed to allocate IOMMU group\n"); > + return PTR_ERR(group); > + } > + } > + > + ret = iommu_group_add_device(group, dev); > + if (ret) { > + dev_err(dev, "Failed to add IOMMU group\n"); > + goto err_group_put; > + } > + > + domain = iommu_get_domain_for_dev(dev); > + if (!domain) { > + /* > + * Get the m4u iommu domain from the m4u device. > + * Attach all the client devices into the m4u domain. > + */ > + priv = dev->archdata.iommu; > + m4udom = dev_get_drvdata(priv->m4udev); > + ret = iommu_attach_group(&m4udom->domain, group); > + if (ret) > + dev_err(dev, "Failed to attach IOMMU group\n"); > + } > + > +err_group_put: > + iommu_group_put(group); > + return ret; > +} Here it looks like you are allocating one group for each device. As I said, all devices need to be in one group. Joerg